Generally, a substrate of a semiconductor, an LCD or the like is manufactured in a highly clean environment such as a so-called clean room. A manufacturing device for a semiconductor wafer or the like disposed in the clean room may include a plurality of processing devices for performing a variety of processes. In the processing devices, in order to enhance the production yield of a product (a conforming product ratio), a process chamber for performing a process is closed airtightly to realize a vacuum atmosphere in the process chamber, thereby maintaining the inside of the process chamber more highly clean to perform the process. Process chambers of the processing devices are connected to a transfer chamber for transferring a product among the processing devices. The transfer chamber can be also closed airtightly. A transfer robot is provided for the transfer chamber, so that a substrate can be transferred to the process chamber from a loadlock chamber for transferring the substrate into or out of the manufacturing device. Transfer devices have been improved to be capable of transferring a product in such a high-vacuum state (see Patent Document 1).
A transfer device 1A shown in FIG. 10 transfers a wafer or the like in a plurality of chambers in an ultra-vacuum atmosphere in a clean room.
The transfer device 1A is disposed on an opening portion formed in portion of a wall of a vacuum chamber 50S (a casing). The transfer device 1A includes a flange portion 11S (a base member), which is attached to the wall of the vacuum chamber 5OS in an airtight state in order to resist a high vacuum in the vacuum chamber 50S.
The flange portion 11S is provided with a fixed shaft 10S (a fixed shaft member) extending into the vacuum chamber 50S. Provided on an outer side of the fixed shaft 10S are hollow operation shafts 21S, 22S (rotary members). The operation shafts 21S, 22S are coaxial to the fixed shaft 10S and are disposed so as to be vertically displaced from each other in a rotatable manner via a bearing.
Provided on an inner side of the operation shafts 21S, 22S and an outer periphery of the fixed shaft 10S is an electromagnetic stator S (an armature). A rotor R using a permanent magnet is provided on an inner periphery of the operation shafts 21S, 22S. The stator S and the rotor R are positioned to face each other. The stator S and the rotor R form an electromagnetic motor M. The stator S is accommodated in a dented portion 13S formed in the fixed shaft 10S. On an outer periphery thereof (an open surface of the dented portion 13S), a partition wall member 14S is welded such that the inside of the dented portion 13S including the stator S is separated from the inside of the vacuum chamber 50S.
On the inner side of the operation shafts 21S, 22S, a resolver-type position detector 40S is provided for detecting positions of the operation shafts 21S, 22S. The position detector 40S is disposed in a region displaced from the motor M in an axial direction of the fixed shaft 10S. Similarly to the motor M, the position detector 40S includes a stator 42S and a rotor 41S. The stator 42S is accommodated in the dented portion 13S of the fixed shaft 10S similarly to the motor M. An outer periphery of the stator 42S is sealed by the partition wall member 14S.
A high-vacuum driving source is formed by the flange portion 11S, the fixed shaft 10S, the partition wall member 14S, the operation shafts 21S, 22S, the motor M and the position detector 40S.
Connected to the operation shafts 21S, 22S is a transfer arm assembly 30S (a drive arm). A pulley 31S is connected to the operation shaft 21S. An arm 32S is connected to the operation shaft 22S. The pulley 31S and the arm 32S can perform a handling of a product such as a semiconductor wafer via a movable mechanism (not shown) provided at an end of the transfer arm assembly 30S.
The transfer device 1A (the transfer robot) is formed by the transfer arm assembly 30S and the driving source.
[Patent Document 1] JP 2000-167792 A